9x-120=5(x-8)解方程,9x-5x=-40+120这一步那下一步的得数应该是160,怎么会是80呢?

问题描述:

9x-120=5(x-8)解方程,
9x-5x=-40+120这一步那下一步的得数应该是160,怎么会是80呢?

20

9X-120=5(X-8)
9X-120=5X-40
9X-5X=120-40
4X=80
X=20

9x-120=5x-40
9x-5x=120-40
4x=80
x=20

9X-120=5X-40
9X-5X=-40+120
4X=80
X=20

9X-120=5X-40
9X-5X=120-40
4X=80
X=20
算这些题的时候要注意正负号!! 40前有个负号!

9x-120=5(x-8)
4x=80
x=20

9x-120=5(x-8)
9x-120=5x-40
9x-5x=-40+120
4x=80
x=20

9x-120=5x-40
4x=80
x=20